Crankcase ventilator



(May 2, 193 C. w. MQKHNLEY CRANKCASE VENTILATOR Filed May 6, 1927 gjwumto c Patented May 2, 1933 UNITED STATES PATENT o FICE f CHARLES w. MCKINLEY, or FLINT, MIcHiemv, Assrenon o A c srAnK PLUG COMPANY, or FLINT, MICHIGAN, A ooaronnrron or MICHIGAN CRANKCASE VENTILATOR Application filed May 6,

This invention relates to a crank case ventilator for an automobile engine.

In the ordinary type of crank case ventilator connected with the carburetor intake, the amount of air passing through the crank case into the carburetor intake is in direct proportion to the amount passing through the carburetor. When the engine is operating at high speed and the maximum current of air is passing thru the crankcase into the carburetor intake, the engine is usually hot and the need for ventilation thru the crank case is much less than at low speeds. The result is the too rapid passage of air through the crank case while the engine is operating at high speed and fine particles of oil are picked up and carried into the intake manifold. This results in high oil consumption.

It is the object of this invention to provide a device which will give a maximum flow of air through the crank case at low engine speeds and prevent a proportionate increase in the flow of the air at high engine speeds. It is a further object of the invention to provide a device which will progressively lessen the rate of increase in the air current from the crank case to the carburetor as the speed of the engine increases.

Other objects and advantages of the in-' vention will appear in the course of the following description, taken in connection with the accompanying drawing, and will be particularly pointed out in the appended claims.

In the drawing, the figure is a side elevation 5 of my improved ventilating system, partly in section and with parts broken away.

The numeral 10 indicates generally the engine crank case provided with an opening 12. Fixed to the crank case over the opening 12 is the air intake or chamber 14. Fixed over the inlet in the air chamber is the air cleaner 16. Pivoted within the air chamber as at 18 is the valve 20. This valve fits against the stop 22 fixed to the sides of the air chamber 14 and is normally held thereagainst by the spring 24. The numeral 26' indicates a tube leading from the crank case into the air chamber 14. The air chamber is provided with a pipe 30 leading to the carburetor.

" The operation of my device will now be 1927. Serial No. 189,406.

described. Within the engine running at: a low speed, the spring 24 holds the valve 20. against the stop 22. With the valve in this position, part of the air taken in through the cleaner passes over the valve 20 directly through the air intake and part is deflected by the valve and passes down through the opening 12 into the crank case. The air en tering the crank case passes out through the tube 26 and back into the air chamber where it mixes with the airenteringover the valve 20 and passes on to the carburetor. As the engine increases in speed the suction from the engine through the air intake increases and air enters through the air cleaner more rapidly. As the rate. at which air enters through the cleaner is increased,-the valve 20 is forced back against. the tension of the spring 24 un til it reaches the dotted line position 32, which indicates the approximate position of the valve when the engine is running at full speed.

It is clear from this description thatas the valve moves from its full line position toward the perpendicular, less and less air will be deflected down through the opening 12 and consequently less and less air will be drawn out of the crank case through the tube 26 back into the air chamber and to the carburetor. The ratio bet-ween the current of air passing over the valve 20 directly to the carburetor and the current deflected through the crankcase by the valve 22 depends on the speed of the engine, the original or idle 7 position of valve 20, the strength of spring 24, the relative size of the valve 22 and the conduit in which it swings, and other factors. It is obvious that by properly proportioning these parts, the current of air passing through the crankcase can be made to decrease steadily from the original position or can be made to increase until a certain engine speed is reached and then decrease during a further increase in speed of the engine. As the valve moves on down from full line position toward the dotted line position, it tends more and more to obstruct the passage of the current of air moving from the crankcase through the tube 26 up into the air chamber, and to a corresponding degree obstruct less and less of the current passing directly through the intake. While the increasing suction through the intake may cause an increase in the rate at which air passes through the crank case and up through the tube 26 into the air intake, the rate of increase in the flow is lessened progressively by the described action ofthe valve 20 as the engine increases in speed. It is obvious that by properly calibrating the spring 24:, any desired cutoff can be obtained.

I claim:

1. The combination of an internal combustion engine having an air intake and a crankcase, conduits leading from said crankcase and joining said air intake alongside of each other, an unbalanced valve in said intake pivoted between said conduits at the point of junction of said conduits and intake, and a spring normally swinging said valve toward the incoming air so that the valve diverts air through one of said conduits into the crankcase but upon increase in flow-of air is swung over to a position partially closing the other conduit.

2. The combination of an internal combustion engine having an air intake and a crankcase, conduits leading from said crankcase and joining said air intake alongside of each other, an unbalanced valve in said intake pivoted between said conduits at the point of junction of said conduits and intake, and a spring normally swinging said valve toward the incoming air so that the valve diverts air through one of said conduits into the crankcase but upon increase in flow of air is swung over to a position partially closing the other conduit, and a stop positioned to prevent moving of said valve to conduit-closing position under the influence of said spring.

In testimony whereof I aflix my signature.

CHARLES W. MCKINLEY. 

